DE-U 87 15 141 has disclosed a cutting tooth which, on the flank facing in the cutting direction, has a cutter which is mounted ahead of a cutter-support region, as seen in the cutting direction. The cutter axis is inclined slightly in the cutting direction. On the advance side, which faces in the direction of advance, the cutter-support region is flush with one end of the cutter, and in the area lying in the opposite direction to the cutting direction, is drawn down toward the tooth root by way of an arch which is slightly convex when seen from the side.
As a result of the cutting advance component of the movement of the cutting tooth, that edge of the cutter which faces in the cutting advance direction and the adjoining part of the cutter-support region are pressed against the earth and consequently are gradually ground down to assume a flatter shape. In the process, a surface which has been ground down essentially perpendicular to the cutting advance direction is produced in this part of the cutter-support region. Since the cutter-support region is drawn down toward the tooth root in the opposite direction to the cutting direction, this surface increases in size as the cutting tooth becomes increasingly worn. The result of this is that the cutting advance becomes ever more difficult as the wear to the cutting tooth increases, since an increasingly large "blunt" surface has to be pressed against the earth. In the cutting advance direction, only the outer edge of the cutter, as seen in the cutting direction, has a cutting function. The adjoining surface is pressed flat against the earth.